I. Field of the Invention
This invention relates generally to an apparatus and method for conducting a home diagnostic testing and screening for sleep related disturbances and, more particularly, to a system that utilizes a patient's own smartphone as a data acquisition and data transfer device.
II. Discussion of the Prior Art
Obstructive sleep apnea is the most common sleep disorder and is responsible for more mortality and morbidity than any other sleep disorder. Sleep apnea is characterized by recurrent failures to breath adequately during sleep, primarily due to obstructions in the upper airway.
Apnea is defined as a complete cessation of airflow. A related sleep disorder, termed hypopnea, is defined as a reduction in airflow disproportionate to the amount of respiratory effort expended and insufficient to meet the individual's metabolic needs. During episodes of apnea or hypopnea, oxygen levels in the brain decrease while the carbon dioxide level rises. This causes the sleeper to awaken. The brief arousals to breath are followed by a return to sleep.
Obstructive sleep apnea is a serious, yet treatable, health problem worldwide. Published reports indicate that untreated obstructive sleep apnea patients are three to five times more likely to be involved in industrial and motor vehicle accidents and have impaired vigilance and memory. Untreated apnea leads to hypertension, stroke, heart failure, heart attacks and other maladies.
The current standard for the diagnosis of obstructive sleep apnea is a relatively expensive overnight sleep study in a hospital or clinic. Here, a variety of physiologic sensors typically involving electroencephalograms, respiratory airflow, respiratory effort, oxygen saturation, snore sounds and body position are fed into an instrument called a polysomnograph (PSG).
Because of the relative expense involved in having the aforementioned type of sleep study conducted, a need exists for a lower cost way to determine whether a PSG sleep study is needed. As a result, several portable sleep monitors have been developed that can be used in a patient's own home as a screening tool.
While home sleep screening protocols measure significantly fewer physiologic parameters than are typically involved in a PSG-based study, the results of home screening tests that measure respiratory airflow and respiratory effort provide enough information to determine whether a person is a candidate for a comprehensive sleep study or whether there is an immediate need for the patient to acquire and begin use of a CPAP device.
Many industries find it essential that their workers be alert during the execution of their job performance. For example, airline crews, over-the-road truckers and hospital personnel and all those who have the safety of the public as a responsibility should be periodically screened for sleep abnormalities. The expensive testing of thousands of employees in PSG-based sleep labs could prove prohibitively expensive while the cost of running a home sleep screening and diagnostic test can be made sufficiently inexpensive that it can be used to sort out only those employees who test positive for disturbed sleep patterns. Such persons would be encouraged or required to undergo a full sleep study possibly as a condition of continued employment. The present invention provides such a low cost screening and diagnostic testing system for at-home use, one that uses a subject's own smartphone as a data acquisition and data transfer device. Thus, the apparatus of the present invention is intended to test patients for a variety of sleep abnormalities. The outcome of the testing procedure is acceptable as a preliminary risk assessment tool as well as a diagnostic tool for sleep disordered breathing, sleep disruption and in some cases sufficient for prescriptions for therapy.
Users of the present invention may typically be a testing service provider or a business corporation that has a need to make sure that its employees are not compromised due to disturbed sleeping. The patient or employee will apply the sensors and follow the test procedure instructions provided via the subject's own cell phone. Once the digitized sensor data is collected over a predetermined test interval, it will be sent via the cell phone to the host computer where a data analysis program will analyze the data and generate a report.